Stoker apparatus



June

J. MOSSHART' I 2551025906 S'IGKER APPARATUS Filed Jul; 29, 1942 sSheets-Sheet 1 1 A'TITORNEY- 7 J 1946- D. J. MOSSHART STOKER APPARATUSFiled 'July 29, 1942 8 Sheets-Sheet 2 INVENTOR Dowmn J. MOSSHRRT.

WITNESSES:

ATTORNEY June 1946- D. J. MOSSHART STOKER APPARATUS Filed July 29, 19428 Sheets-sheaf. s

I I INVENTOR DONHLD J. MOSSHRRT.

ATTORNEY June 25, 1946. ss -r STOKER APPARATUS Filed July 29, 1942 8Sheets-Sheet 4 INVENTOR ATTORNEY June'ZS, 1946.

D. J. MOSSHART STOKER APPARATUS Filed July 29, 1942 8 Sheets-Sheet 5INVENTOR DONRLD J. Moss HRYRT.

ATTORNEY June .1946. D. J. MOSSHART STOKER APPARATUS Filed Jul 29, 19428 Sheets-Sheet 6 INVENTOR ama;

ATTORNEY DONRLD J. Mossnnm:

WITNESSES:

Patented June 25, 1946 UNITED STATES PATENT ,orslcs STOKER APPARATUSDonald J. .Mosshart, Ardmore, Ba... assignor-to Westinghouse. ElectricCorporation; East Pittsburgh,.Pa., a. corporation of PennsylvaniaApplication July 29, 1942, SeriakNo: 52.,7 59

37 Claims.

fiLlld-(JOOIBCI center elements and complemental air-cooled sideelementsadapted to interlock therewith to form the complete tuyre members.

These and other objects: are;effected bythe invention as will beapparent from the following description-and claims taken in connectionwith the accompanying drawings, forming a part of this application. inwhich:

Fig- 1 is a perspective'view of multiple-retort underfeed stokerembodying the presentinvention, portions of :the apparatus being omittedin order to more clearly disclose features ofthe invention;

Fig. 2 is aside-'elevational view, partially in section; of--a stokertuyre'row together withthe cooling system therefor and variousassociated parts;

Fig. 3 is a broken plan-view of a single tuyere row;

Fig. 4 isa side elevational'view oftheystructure shown in Fig. 3;

Fig. 5 is a front elevational viewof one of thetuyre center membersshown in. Figs. 3-and 4 Fig. 6 is a transverse sectional view takenalong the line VI--VI of Fig. 4, looking-in the direction of the arrows;

Fig. '7 isanexploded side-elevational view, of

the structure as illustrated inFig. 6;

Figs. 8, 9 and'lil are plan, front and'rearelevational' views,respectively, of one of thertuyere side members shown in Fig. 7;

Elg. 11 1s;a plan view. of one of tne tuyere-center members in assembledrelation with. respect to its supporting structure, but withits-complemental side tuyre members :arranged in exploded relationthereto;

Fig. 1. is a plan view of the upper and-lower endmembers of a tuyre row;

-.F"ig. 13 is a longitudinal .sectional.view taken along the lineXIIIXIII of Fig. 12,-looking in thedirection of. the arrows;

Fig. v14 is a side elevational view of a tuyre .side-wall row,with;-portions. thereot brokenaway for the sake of clearness;

Figs. 15. 16 .and 17 Mare transverse sectional views; taken along; thelines, andXVII+XVII.-.respectively, of-Eig. 14,;loblging in thedirections. of.=the arrows;

'F ig ..18.is a plan viewsimilarto Eigl3; butshow- .ing-, a modifiedconstruction;

.Eiga19 .isaa side elevational view of the structure q shown .in i Fig.18, -;--.with portions, .thereof ;-broken away forthe-"sake of'clearnessand,

E-ig'. 20 is va;tnamsverse sectional view... taken .along the lineXX-eXX.ofiEig. 19, looking m the direction of the arrows.

Referring-now to the drawingstmore incdetail,

there is.-sho;wn, at I ll,,-.a: fluid cooledestokergembodyimg thepresent -invention andecomprising alternately;arranged retorts lland,tuyere-=rows 12, together. with side WaILtuyer-e rows. l3. Fuel--is-;fe,d to t e I i h ou t e amopenm s [hat theupp,er;;-ends of. the.retorts and is vadvanced along the latter to the rear-of thestoker s bymeans of secondaryrams I6, which, asiherein illustrated; areof;conventional -construction:..and form; no=partof-the presentinvention.,Airedis- ',tributin'g box structure I l is provided atthe'upper "endsof .the retorts. l I,;. and qtuyre rows {12. kforisupplyingrsecondarygair toethe combustion; chamher in the: usualmanner.

.2 As;.;best; illustrated" .in .;Fig. 6,-, each. tuyre, =-row---comprises spaced tuyere row side walls l-ayand l 9, .the space :2therebetween being adapted to; -reiceivesair; from .the...p1e .mchamber, 22, therebeslow-(Fig. 2). "Theside walls, l8 ;and;l9 .areprovided with inwardly-directed la teral;- flanges,.-,23

-and 2A.irespectivelye e r s. a -part a -su port for the:.tuyre.iassem-blyi tot be hereinafter described.

:A zstructlutal gsupportingemember 2 6 extends --longitudina:l1y .oflthe:t yere iroweintenne atehe -tuyerezsidei walls. Mand -.119anode-provided at its uppereedge. with lateral .:.flanges 21. Iormin;.an u per supnortingesu ia preI yJYin -in.the plane; .of the,;:upp ersurfaces .of theflanges. 23 and-2 4. ofthe tuyre -;r0.w: sidewalls.

rosts;1upon:.;.and;=.is supported by theilanges 11 and comprisesgia.base- 2 hav ng end supporting walls 30 and an intermediate supportingwall-e32.

T es -wa l .l Q ther w th l ten webs 33.

.cave v,in -cross. section. concave surface. is

carrya longitudinallyextending .suppont.34,-,con-

' ,provided with. SDacd, ,raiSfd. bearing surfacesi35 wdthb ls 9, eddlemem enhasn tches "31 in its.side'edgesforitheireceptionofifasteningmeans to" be described later; Preferably these tube saddle members areof considerably less length than the overall length of a tuyere row, aplurality of such saddle members being assembled in end-to-end relationto provide a longitudinally-extending supporting structure for a tube 40extending from end to end of the tuyere row. j

The tube 40 has its 1 terminal portions threadedly connected to andsupported by upper and lower hollow end castings 4i and 42,respectively, at opposite ends of the tuyere row (Fig. 13). Coolingfluid, for example water, is supplied to the lower end casting 42 fromthe header 43, for passage through the tube 40, by means of theconnecting supply pipes 44 and 45 (Fig. 2). The cooling fluid, uponleaving the tube by way of the hollow upper end casting 4|, is conductedto a heat exchanger 41 by connecting pipes 48, 49 and 50. After givingup a predetermined amount of heat in the heat exchanger, the cooledwater is returned to the supply header 43 by way of the .return pipes52, 53, 54 and 55.

- While the cooling system herein disclosed is independent of the boilerwater system and involvesthe use of an independent heat exchanger, itwill be apparent to those skilled in the art that the invention is notlimited to such a system but may well include other arrangements, forexample, passing boiler water'through the tubes 40. The closed coolingsystem with the independent heat exchanger, herein illustrated, forms nopart of the present invention and is the subject matter of my copendingapplication Serial No. 449,-

725, fi1ed July 4, 1942.

eferring again to-the tuyere assembly, illustrated in Figs. 1, 5, 6, '7and 11, a tuyere cap or center member 51 isarranged in heat-transferrelationship to the tube and comprises an elongated body portion 58having a convex upper surface 59 and a concave under surface 6|, forming the bottom of a groove 52 of inverted U for- 'mation. A plurality ofstuds 63 are threadedly mounted in the elongated body portion 58 of thetuyere center member and extend downwardly therefrom through the sidenotches3l of the tube saddle member 28, and are secured at the underside of the flanges '21 of the supporting structural member 26, by nuts65 to retain the tuyere center member in heat-transfer relation to thetube 40.

Each tuyre center member forms one section of a tuyere row, a pluralityof these sections being assembled in end-to-end abutting relation toform a covering for the tube 40 and extending from the u pper hollowtube casting 4| to the lower casting 42.

Each tuyere center member includes a plurality of tuyere nose portionsformed integral therewith and so positioned that their upper surfacesprovide a substantially horizontal fuel-supporting structure for fuelfedthereto from theretorts l'l. Inasmuch as the tuyere row assembly,

" and the tube 49 with which the assembly is assoelated, are inclineddownwardly in the direction of fuel feed, the tuyre nose portions 61 aredisfposed at a material angle to the longitudinal axis of thetube 40 inorder that the fuel-supporting jsur'faces'they present may besubstantially hori- Eachtuyre nose portion extendslaterally in'bothidirections fromfthe tuyere center member bodyjportion 58, thelaterally-extending portions "having their rearward edgesrabbeted, atB8, to '1 provide 'a ledge or step 69, forapurpose to be hereinafterexplainedl" 4 The rabbet68 is formed with a reentrant portion orrearwardly-opening notch I l for the reception of a forwardly-extendingtongue 19 formed on a complemental tuyere side member 15.

A pair of tuyere side members, one left-hand and one right-hand, isassociated with each tuyere nose portion 61 to provide therewith acomplete tuyere member. Each tuyre side member is provided at itsforward edge with a rabbet 16 providing an overhanging lip 11 adapted tooverlie the rearwardly-projecting lip 69 formed on the mating edge ofthe tuyere nose portion. This overlapping relation of the lip 11 andledge 69 serves to prevent fine fuel falling through fromthe fuel bed tothe plenum chamber at the joints between the tuyere nose portions andthe tuyere side members.

The tongues 12 and the notches ll interlock the tuyere side member withrespect to the center or nose member to prevent lateral displacement ofits forward end (the terms front or forward and rear or rearward areused herein in reference to the direction of fuel feed) Each tuyre sidemember 15 is provided at its rear edge with a centrally-disposeddepending lug 8| serving to separate an inner-inclined under surface 82from an outer-inclined under surface 83, the inclination of thesesurfaces corresponding to the inclination of the tuyere row side wallflanges 23 and 24, whereby the rearward end of each tuyre side member issupported at its outer edge by the outer-inclined surface 83 hearing onthe flange 23 or 24, and its inner-inclined surface 82 bearing on theflange 21 of the central supporting. member 26. The depending lug 81engages the inner edge of the flange 23 or 24 and prevents lateraldisplacement of the rear end of the tuyere side member.

Each tuyere side member is provided with an opening 84 therethrough forflow of air from the plenum chamber 22 and air space 2| to the fuel bedcarried by the tuyre assembly. The tuyere side member has adownward1y-dependihg rib 86 extending longitudinally of the outer edgeof its A plurality of upstanding lugs 81 are formed on the upper surfaceof the tuyre side member and serve to direct the flow of air passingupwardly through the opening 84 in said member. Flow of air laterallyfrom the vicinity of the passage 84 is prevented by the depending flange86 on the adjacent tuyere side member thereabove, as best illustrated bythe dotted lines shown in Figs. 3 and 4.

In Figs. 18, 19 and 20, there is illustrated a modification of theconstruction just described, which differs therefrom in respect to thetuyre center member and its support. In this construction the tube 40 isomitted and tuyere center member I 00 is provided with alongitudinally-extending bore "H, the bores of adjacent members beingconnected by nipples I02 to provide a continuous passage for coolingmedium from the lower to the upper end casting. Each of these tuyerecenter members is provided with tuyre nose portions and cooperatingtuyre side members identical with those described in connection with theearlier construction.

Due to the absence of an independent tube, the support for the tuyrecenter member is modifled and comprises an elongated H-shaped saddlemember I03 to which the tuyre center member is connected by stud I04,the saddle member being secured to the main supporting structural member26 by bolts I05.

Regardless of which construction is used for cooling the tuyere rowassemblies, the side wall eao eoe -ti-iyererows may =be-coo1ed by theconstruction "illustratedin-Figs. 14, 15, 16 and 17. *Inth'isarrangement, there are provided flanged-structural supporting"members III! --'and III, providing therebetween an air space i I I2communicating with the plenum chamber' 22. An angle support member II3-has a bottom "flange I I4 resting upon the supporting members Iii andII I and provided-w'ith openings I I6 thereth'rough for fiow'of air fromthe plen-um'chamber. The angle-support includes an inclined inner wall--construction formed by spaced ribs I II'providing openings I I 8therebetween; the outer surfaces of the ribs being concaved toprovide-cradle structures I59 for the reception of alongitudinally-extending cooling 'tu-be IZI. T-his tube has-its'terminalportions "threadedlymountedin and supported-by an up "per end castingI22 and a lowcr 6nd casting I23, "cooling' fluid being supplied to thelatter from the main supply' h'eader' ib by the connecting pipes I24an'd I 25- for now through the tube. After passage through the tube I2Ithe cooling fluid is "conducted from the hollow upper end casting I22 tothe heat exchanger 41 through 'th'e discharge pipes "I27 and I23. Theupper and lower end castings are-substan- -tiallyidentical and referenceis made toFig. 15, "which is a sectional View through the upper "endcasting, for-a description of the construction of both. The casting isprovided with an inner face -'plate-l2I --having a plurality of'peri'orations 'itb "extending "therethrough for passage of air from theplenum chamber to the fuel bed adjacent the face-plate I29. -The platehas depending lugs -I32atits upper edge and similar lugs-lsii'at its".:lower edge, the former being -adapted to extend -behind the upperedge of the angle-support I I3a -=an'd the lowerin hooking inside theflanged edge of the supporting member III. Thespace between the anglesupport II3a andthe furnace side wall I 34 preferably is packed withsuitable material I35, the latter being supported from benea'thby thestrip I33.

Between=the upper'an'd lower end castings, the tube' 'IZI is covered byface plates I 38 (Figs. 16 and '17 having perforationsl33 therethroughfor passage of air for'combustio-n purposes. The face plates areprovided on their sides adjacent the tube'wi th parallel spaced ribs I48having "formed therebetween a-concave trough I4I adapt- -ed 'toclosely'fit the tube IZI in heat-transfer r'lationthereto. A 'lug I42depends from the upper edge of each plate and projects-downwardlyoutside of the angle support I I3, the space "between the angle supportand the furnace side wall I34 being filled with packing I35 retained bythe supporting strip I36, as in the vicinity of the upper and lower endcastings.

A plurality of bolts I43 serve to retain the face "plate I38 in positionwith respect to the anglesupport II3, with the tube I2I clampedtherebetween. Nuts I44, positioned in recessed slots I45 of the anglesupport H3, are threaded upon the bolts I43.

"While the invention has been shown in several forms, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various other changes and modifications without departingfrom the spirit thereof, and it is desired, therefore, that only suchlimitations shall be placed thereupon as are specifically set forth 1 inthe appended claims.

What is claimed is:

-l-. A tuyre row comprising a pair of spaced sidewalls*and-a-tuyere"assembly bridging the sides lie in'the planecontaining the "sidewall space therebetween; :said ltuyreassemblycomprising a longitudinally 'extending "tube, 1 longi-"tudinally-aligndtuyere cap members completely overlying said "tube" inheat transfer relation "thereto, and. tuyere side-members cooperatingwith said tuyere cap members at both sides of the latter toprovide"fuel-supporting surfaces v overlying the tuyere rows.

2. A tuyere row comprising apair of spaced side wallsan'datuyreassembly-bridging the space 1 therebetween; said tuyre assembly'cornprising a longitudinally-extending" tube; "means 'for supportingsaid tube'intermediate its ends; longitudinally-aligned tuyre capmembers overlying-said tube; each 'of said tuyre capmembers includingone or -more tuyre nose. portions; -means for retaining saidtuyere'cap'members in heat transfer engagement with said "tube and apairof 'tuyere-side members complementally interlocked" with each tuyerenose portion.

"3. A'tuyre row comprisinga pair of sidewalls "spaced apart to providean air-space and'having their upper edges disposed i'n'a common plane; astructural member extending longitudinally .of said air space and havingan upper-surface-whose upper edges; a cooling tube carried by-saidstructural member; and a row of multiple-part tuyre plates bridgingsaidspace, each tuyre plate comprising a central part carried bysaidcoolingtube in heat-conductive relation to the latterand'lateral;parts supported on the upper edges of the side walls and of thestructuralmember.

i lq structureas specified in claim 3,"including interlocking-means onthe central and lateral parts of each tuyre plate.

-5. A tuyere row comprising a'pair of spaced side 'wallsand a tuyreassembly bridging the spacer therebetween; 'saidz'tuyreassemblycomprising a longitudinally-extending tube, means beneath saidtube for supporting the'same, longitudinally aligned tuyr cap membersstraddling said-tube and having surface-to-surface rcontact with "its:upper surface, means fastening 'the'tuyre cap'members to thetube-supporting means with theatube clamped therebetween, and

, tuyre side members interlocked with said tuyre cap." members.

6. A tuyre row comprising a pair ofspaced :sidewalls and Ya tuyereassembly bridging thespace' therebetween; said tuyere assemblycomprisingra longitudinally-extending tube inclined I from thehorizontal; means for supporting said tube intermediate its-ends, tuyerecap members cdisposed 'in heat transfer relation to said tube, each ofsaid tuyre cap members including one I or more tuyere nose portionslying in approxi- -mately"horizontal planes, and tuyere side memberscooperating with said tuyere nose portions --and lying in the sameplanes as the nose portions with which they cooperate and extendinggenerally rearwardly therefrom, considered in the direction of fuelfeed.

7. Structure as specified in claim 6, including interlocking means onsaid tuyere nose portions 1 andsaid' tuyre side'members.

-8. 'A tuyre'row' comprising apair of spaced side Walls and a tuyereassembly bridging the space therebetween:- said tuyere assembly com.-

prising a longitudinally-extending tube; means for supporting said tube'intermediateits ends; longitudinally-aligned tuyere cap members .onsaid tube; means for maintaining said tuyere cap members and said tubein heat transfer relation, each of said tuyre cap memberscincludingvoneor more tuyre nose portions extending laterally 7 at both-sides thereof;and a pair of tuyere side members complementary to each of said tuyrenose portions and extending laterally and rearwardly thereof consideredin the direction of fuel feed and defining therewith completefuel-supporting tuyre members.

9. Structure as specified in claim 8, including interlocking means onsaid tuyere nose portions and said tuyere side members.

10. Structure as specified in claim 8, wherein the tube is inclined withrespect to the horizontal and a portion of each tuyere side memberunderlies an adjacent tuyre nose portion and is spaced therefrom, saidstructure including a plurality of upstanding spaced lugs on the uppersurface of each-of said underlying portions of the tuyere side members,the spaces between said lugs constituting air distributing passages.

11. Structure as specified in claim 8, wherein each tuyere side memberhas an opening therethrough overlying and in communication with thespace between the tuyere row side walls for passage of air from saidspace.

lugs on the upper surface of each of said underlyingjportions of thetuyere side members, the spaces between said lugs constituting airdistributing passages.

13. A tuyere row comprising a pair of spaced side walls and a tuyreassemblybridging the space therebetween; said tuyre assembly comprisinga longitudinally-extending supporting member, a plurality oflongitudinally-aligned saddle members carried by the supporting memberand having concaved upper surfaces providing a longitudinally-extendinggroove, a tube disposed in said groove and supported intermediate itsends by said saddle members, a plurality of longitudinally-alignedtuyere cap members having concaved under surfaces providing alongitudinally-extending groove adapted to closely receive the upperconvex surface of said tube, means for retaining said tuyre cap membersin heat transfer relation to said tube, and tuyre side members extendinglaterally from and cooperating with said tuyre cap members.

14. Structure as specified in claim 13, wherein the means for retainingthe tuyre cap members inheat transfer relation to the tube comprisesstud bolts secured at one end to the lower sides of said tuyre capmembers and at their other ends to the longitudinally-extendingsupporting in the direction of fuel feed, and each tuyere having anupper fuel-supporting surface whose inclination from the vertical ismaterially greater than that of the tube.

16. Structure as specified in claim 15, wherein the upperfuel-supporting surface of each tuyere is approximately horizontal. 17.A tuyere row comprising spaced side walls and a tuyere assembly bridgingthe space therebetween, said tuyere assembly comprising 2.Iongitudinally-extending tube inclined downwardly in the direction offuel feed, supporting means for said tube, a row oflongitudinally-aligned tuyre cap members disposed in heat transferrelation to said tube, each of said tuyere cap members including aplurality of tuyre nose portions each spaced vertically from theadjacent nose portions and projecting forwardly in the direction of fuelfeed beyond the adjacent nose portion thereabove, and a pair of tuyereside members extending generally rearwardly from each tuyere noseportion and providing therewith a complete tuyere.

18. Structure as specified in claim 17, wherein said tuyere side membersinclude means defining a plurality of generally horizontal airdistribution passages between adjacent tuyres,

19. A tuyre row comprising spaced side walls and a tuyre assemblybridging the space therebetween; said tuyere assembly comprising a, rowof longitudinally-aligned tuyere center members, each of said membersincluding a plurality of tuyere nose portions, a pair of tuyre sidemembers extending generally rearwarclly from each tuyere nose portionconsidered in the direction of fuel feed and providing therewith acomplete tuyre, and means providing a conduit extending from end to endof said row of tuyre center members in heat transfer relation to saidtuyre nose portions.

20. Structure as specified in claim 19, including interlocking means onthe tuyre nose portions and the tuyre side members.

21. A tuyere row comprising spaced side walls and a tuyre assemblybridging the space therebetween; said tuyre assembly comprising firstmeans providing a longitudinally-extending conduit, second means in heattransfer relation to said first means and including a plurality oftuyere nose portions, and a pair of tuyere side members extendinggenerally rearwardly from each tuyere nose portion considered in thedirection of fuel feed and providing therewith a complete tuyre.

22. Structure as specified in claim 21, including interlocking means onthe tuyre nose portions and the tuyere side members.

23. A tuyre row comprising a pair of spaced walls and a tuyere assemblybridging the space therebetween; said tuyere assembly comprising a rowof longitudinally-aligned hollow body members arranged end to end, meansproviding communication between the. hollow interiorsof adjacent bodymembers whereby there is provided a continuous passage extending fromend to end of the row, a plurality of tuyre nose portions formedintegral with each of said body members, and a pair of tuyere sidemembers extending generally rearwardly from each tuyre nose portionconsidered in the direction of fuel feed and providing therewith acomplete tuyere.

r 24. A tuyre row comprising a pair of spaced walls and a tuyereassembly bridging the space therebetween; said tuyre assembly comprisinga row of longitudinally-aligned body members arranged inend-to-endrelation, said row being inclined relative to the horizontaland each of said body members having a passage extending therethrough,means connecting adjacent ends of the passages of adjacent body memberswhereby a continuous conduit is provided extending from end to end ofthe row, each of said body members having formed integral therewith aplurality of tuyere nose portions each spaced vertically from theadjacent nose portions and projecting forwardly in the direction of fuelfeed beyond the adjacent nose portion thereabove, and a pair of tuyereside members extending generally rearwardly from each tuyere noseportion and providing therewith a complete tuyre.

25. Structure as specified in claim 24, wherein said tuyere side membersinclude means defining a plurality of generally horizontal airdistribution passages between adjacent tuyeres.

26. A tuyere side member adapted for assembly on a stoker of themultiple retort type, said tuyere member comprising an elongated bodystructure having part of the rearward portion of its lower surfaceinclined upwardly towards the rear edge and adapted to rest upon thecorrespondingly inclined upper edge of a tuyere row side wall, aforwardly-projecting lip at the front edge of the body structure adaptedto mate with a ledge on a complemental tuyere center memher, said liphaving a recess in its front edge adapted to receive a mating projectionon the complemental tuyere center member, whereby lateral displacementof the forward portion of the tuyere side member is prevented, and adownwardJy-projecting lug on the inclined lower surface adapted to tbutthe tuyere row side wall, whereby lateral displacement of the rearportion of the tuyere side member is prevented.

27. A tuyere member comprising an elongated body structure having avertical opening therethrough for passage of air and having at its frontend a lower bearing surface for supporting said end, means carried bysaid end for preventing lateral displacement thereof, means at the rearend of the body structure adapted to engage a supporting structure toprevent lateral displacement of said rear end, said body structurehaving an inclined lower bearing surface for supporting said rear end,and spaced air-directing means extending vertically from the uppersurface of the body structure.

28. A tuyere side member adapted for assembly on a stoker of themultiple retort type, said tuyere side member comprising abody structurehaving part of the rear portion of its under surface inclined to matewith a correspondingly inclined support, a forwardly-projecting lip atthe front edge of the body structure, and means carried by said bodystructure for preventing lateral displacement thereof.

29. Structure as specified in claim 28, wherein the body structure isprovided with a vertical opening therethrough for passage of air, andincluding a plurality of air-directing elements.

30. Structure as specified in claim 28, including a plurality of spacedair-directing elements extending vertically from the upper surface ofthe body structure.

31. A tuyre cap adapted for assembly on a tube of a fluid-cooled stoker,said tuyre cap comprising an elongated body structure having an arcuatetube-receiving portion, and a plurality 10 of tuyere elements extendinglaterally from said body structure.

32. A tuyere cap adapted for assembly on a tube of a fluid-cooledstoker, said tuyere cap comprising an elongated body structure having atube-receiving groove in its under surface, and a plurality of tuyereelements extending laterally from said body structure.

33. A tuyre cap adapted for assembly on a tube of a fluid-cooled stoker,said tuyere cap comprising an elongated body structure having an arcuatetube-receiving groove in its under surface, a plurality of tuyere noseelements integral with said body structure and adapted to cooperate withcomplemental tuyere side elements to provide complete tuyere members,and means at the rear edges of said tuyere nose elements adapted toengage with and prevent lateral movement of the adjacent edges of thecomplemental tuyreside elements when assembled therewith.

34. A tuyere cap adapted for assembly on a tube of a fluid-cooledstoker, said tuyere cap comprising an elongated body structure having atube-receiving groove in its under surface, a plurality of tuyere noseelements integral with said body structure and adapted to cooperate withcomplemental tuyere side elements to provide complete tuyere members,rearWardly-extending lips at the rear edges of said tuyre nose elementsadapted to be disposed in lapping rela tion to mating lips at adjacentedges of the complemental tuyere side elements when assembled therewith.

35. A tuyere center member adapted for use in a fluid-cooled stoker,said member comprising an elongated body structure having a fluidpassage extending therethrough from end to end, and a plurality oftuyere nose elements integral with said body structure and adapted toengage cooperatively and extending laterally from opposite sides thereofwith complemental tuyre side elements to provide complete tuyre members.

36. A tuyere center member adapted for use in a fluid-cooled stoker,said member comprising an elognated body structure having a fluidpassage extending therethrough from end to end and adapted to besupported in an inclined position, and a plurality of tuyere noseelements integral with the body structure and extending laterallytherefrom in spaced relation at opposite sides thereof, said tuyre noseelements being adapted to present upper fuel-supporting surfacesinclined at a greater angle to the vertical than the inclination of thetuyre center member when in its supported position.

37. A tuyere center member adapted for use in a fluid-cooled progressivefeed stoker, said member comprising an elongated body structure adaptedto be supported in an inclined position and having a fluid passageextending therethrough from end to end, a plurality of tuyre noseelements integral with the body structure and extending laterally fromboth sides thereof and being adapted to present approximately horizontalupper fuel-supporting surfaces when the tuyere center member issupported in inclined position, and lips at the rear edges of the noseelements adapted to lap mating lips on complemetal tuyere side memberswhen assembled.

DONALD J. MOSSHART.

